The biggest winter storm of the season affected Iowa, Illinois, and Missouri from the evening of 4 January to the morning of 6 January.  A series of low pressure areas tracked from the Central and Southern Plains up through the Ohio Valley while arctic high pressure remained over the Northern Plains. The dominate mechanism for the precipitation was isentropic lift and came in two waves; the first during the evening of 4 January to the pre-dawn hours of 5 January.  A lull in the heavier precipitation occurred during the morning of 5 January with the second round beginning in earnest by mid-day and continuing into the pre-dawn hours of 6 January.  Shallow arctic air south of Interstate 80 resulted in a significant ice storm with mainly snow north of Interstate 80.  Winds during the storm were generally 10 to 20 mph with some gusts in the 20 to 25 mph range.	For some areas it was the largest storm (snow wise) in the past 3 to 6 years.  In Delaware County Iowa, 6 people were indirectly injured near Manchester when their van slid into a ditch on U.S. 20.  In Mt. Vernon, Iowa, part of a building collapsed due to the weight of the snow. For the Tipton Iowa School District it was the first time in memory that 4 consecutive days of school were missed due to winter weather.  This was due to 2 other ice events that occurred on 3 and 4 January.	The axis of the heavy snow ran from around Ames to near Waterloo, Iowa. Snowfall amounts of 10+ inches were common in this band and as far south as U.S. 30.  Heavier snow amounts included 15 inches in Buchanan County at Jesup, 13 inches at Edgewood in Delaware County, 13 inches at Dyersville in Dubuque County, 13 inches in Galena and Warren in Jo Daviess County Illinois, and 12 inches in Cedar Rapids (Linn County) and Scotch Grove (Jones County).	South of the heavy snow band were snow amounts of 3 to 8 inches that mixed with sleet or freezing rain but ice accumulations were generally less than 0.25 inch.  Snow amounts tapered off to 3 inches or less south of a Hedrick, Iowa to Princeton, Illinois line.	Significant icing occurred south of a Hedrick, Iowa to Princeton, Illinois line due to a shallow surface layer of arctic air.  Ice accumulations ranged from 0.25 to 0.80 inches with unofficial amounts of around 1 inch.  Some of the heavier ice accumulations; 0.75 inches at Salem in Henry County Iowa, and Columbus Junction in Louisa County Iowa.  Ice accumulations of 0.25 to 0.75 inches were common across Van Buren, Washington, Lee, Des Moines, and Jefferson Counties in Iowa; Mercer, Henderson, Warren, Hancock, McDonough, Southern Henry, Bureau, and Putnam Counties in Illinois.  Across Clark and Scotland Counties in Northeast Missouri, ice accumulations of up to 0.50 inch were common.

Heavy Snow in JO DAVIESS, ILLINOIS
From 05-JAN-05 18:00:00 to 06-JAN-05 08:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Heavy Snow in STEPHENSON, ILLINOIS
From 05-JAN-05 22:00:00 to 06-JAN-05 08:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Heavy Snow in WHITESIDE, ILLINOIS
From 06-JAN-05 01:00:00 to 06-JAN-05 08:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in WARREN, ILLINOIS
From 05-JAN-05 05:00:00 to 05-JAN-05 14:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in HENRY, ILLINOIS
From 05-JAN-05 05:00:00 to 05-JAN-05 13:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in HANCOCK, ILLINOIS
From 05-JAN-05 03:00:00 to 05-JAN-05 16:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in BUREAU, ILLINOIS
From 05-JAN-05 08:00:00 to 05-JAN-05 14:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in MCDONOUGH, ILLINOIS
From 05-JAN-05 08:00:00 to 05-JAN-05 15:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in MERCER, ILLINOIS
From 05-JAN-05 06:00:00 to 05-JAN-05 14:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in HENDERSON, ILLINOIS
From 05-JAN-05 03:00:00 to 05-JAN-05 15:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER

Ice Storm in PUTNAM, ILLINOIS
From 05-JAN-05 08:00:00 to 05-JAN-05 16:00:00 (CST)
Property damage: 10K
Reported by: TRAINED SPOTTER